The UK certainly had a major biological weapons programme to develop anthrax in the second world war, as Steven Rose asserts (Letters, 20 September), but his statement that "Churchill had to be energetically dissuaded" from using it is wrong. With the help of the Guardian letters page, among others, the late Professor RV Jones and I spent much time in the 1980s showing that this allegation was a myth, based on a misreading of documents about the V-weapons crisis of July 1944. Churchill wanted to use poison gas in response to the V2 rocket threat. He did not ask for germ warfare to be considered, but the chiefs of staff looked into its practicability anyway. They concluded that gas would be counterproductive, whereas sufficient anthrax bombs were simply not available. It was gas, not anthrax, which they dissuaded Churchill from using. This episode is covered in Martin Gilbert's biography of Churchill, in RV Jones's Reflections on Intelligence and in appendix 8 of my book, Changing Direction. Julian LewisCadnam, Hampshire